RU2571669C2 - Electronic unit for sensor control of coordinate machine - Google Patents

Abstract

FIELD: physics; control.

SUBSTANCE: invention relates to sensor control of coordinate machines and can perform the role of a device for protecting an operator and a device for automatic monitoring of correct execution of an article processing program. The device comprises an infrared sensor frame, an information processing unit linked to a data communication unit, configured to be connected to the computer of the machine, as well as an imaging unit in the form of a digital projector. Said frame has a rectangular loop which can be placed on the surface of the work table of the machine and includes a line of infrared LEDs and oppositely lying infrared photosensors.

EFFECT: invention enables to create a sensor interface for developing article processing programs and controlling a coordinate machine, simplifies and provides safer working conditions of the operator.

4 cl, 3 dwg

Description

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The invention relates to the following classes of devices:

1. Regulatory and control systems of general purpose.

2. Electrical devices for processing digital data.

3. General safety devices.

The described unit can be used as a tool for touch control of the machine, and also perform the function of touch input of control programs, as well as defining cutting contours using CAD, preinstalled on a computer connected to the machine. In addition, the touch control unit can act as a safety device, tracking the presence of the operator in the immediate vicinity of the working surface of the machine during the execution of the processing cycle. The latest application is automatic tracking of the correct execution of the product processing program (control of the movement of the machine tool).

A patent search was carried out in the above areas, as a result of which a number of analogues were identified.

In the patent RU 2288808 (08.02.2005) “Device for precision control of part processing on high-precision CNC equipment” a device is described that relates to the field of active control of part processing.

An object of the invention is to increase the geometric accuracy of surfaces during precision processing of parts such as bodies of revolution on high-precision equipment with CNC in real time.

The problem is solved in that an optical sensor, an analog-to-digital converter and a computer are introduced into the device containing the signal amplification unit, actuators, cutter and part, which makes it possible to determine the difference between the required part size value and the current part size received from the optical sensor in real time. The output of the optical sensor is connected to the input of an analog-to-digital converter. The output of the analog-to-digital converter is connected to the input of the computer. The computer output is connected to the input of the signal amplification unit. The output of the signal amplification unit is connected to the inputs of the actuators, the outputs of which are connected to the inputs of the cutter and tailstock. The use of these connections in the device will allow to eliminate the disturbing effects acting on the part in real time by moving the cutter by the actuators, thereby increasing the geometric accuracy of the machined surfaces of the parts on high-precision CNC equipment.

The precision control device for processing parts on high-precision CNC equipment operates as follows. Implementation of the operation of the device was carried out using the example of center turning of the surfaces of a part using CNC equipment.

An electric signal of the current value of the size of the workpiece surface from the optical sensor is fed to the input of an analog-to-digital converter, and then the digital signal is transmitted to the computer input, where it is compared with the required part size. If the size matches, then processing continues. If it does not match, then it is necessary to calculate the compensation value. In a computer, the total value of the disturbing actions at an arbitrary point is determined by the formulas.

The principles of operation of this device are largely consistent with the principles of operation of the claimed invention. However, the technology itself involves tracking the result of processing, and not the process itself, since the unit measures and processes the results of the cutting tool affecting the workpiece, which in turn will lead to undesirable consequences, including scrap, damage or wear of the tool.

Patent RU 2432233 “A device for controlling the movement of a cutting tool when machining parts on a machine” describes a device that relates to automatic control systems, in particular to servo systems, the object of which is an executive motor with a load on the shaft, including with elastic couplings and clearance, to which increased demands are placed on accuracy, speed and stability of dynamic characteristics. The technical result consists in increasing the accuracy of regulation of the trajectory of the relative movement of the tool and the workpiece during processing. The device contains an error identifier, which is a mathematical model of an automatic control system that is programmed and placed on a computer. The simulation of the automatic control process on a personal computer is carried out synchronously with the real process of processing the part on command from the CNC device. The control system for the accuracy of processing works as follows. The CNC device generates a control signal, which will be fed to the first input of the adder, a regulator, which is a system for automatically controlling the movement of the machine drive, a power amplifier, an executive motor, a kinematic system of the machine and a control object, which implements the process of processing the parts by cutting with a given accuracy. In order to improve the accuracy of mining, a correction signal is introduced, which is generated by the determinant of the deviation of the calculated tool path of the cutting tool at the command of the CNC device, which is a signal of the deviation of the calculated tool path from the specified one. For this, a mathematical model of an automatic part processing control device is used, which is a complete analogue of a real system.

Additionally, the model takes into account the elastic deformation of the workpiece due to the fastening scheme and the action of the cutting force that occurs during processing. Formed by the determinant of deviation of the calculated trajectory from the given error signal, it passes through the amplifier to the second input of the adder, forming a control loop along the computational output coordinate. At the same time, a feedback signal is supplied to the third input of the adder, due to kinematic errors of mechanical transmissions, a change in the moment of resistance on the load shaft and the motor, as well as the counter-emf of the engine. Given the inertia of the control device, the feedback signal will come to the adder with a delay compared to the driving signal of the CNC device and the signal that passed through the determinant of the deviation of the calculated path of the cutting tool from the given one and the amplifier. In this case, the last two signals are summed, and the resulting signal is processed throughout the control circuit in the blocks.

The disadvantage of this invention coincides with the disadvantage of the device described in the previous patent RU 2288808: the technology monitors the result of the impact of the tool, and not its direct movement, which is superimposed on taking into account a large number of errors, despite the accuracy of the equipment and elements used, which negatively affects the cutting tool and product blank.

Patent RU 2438849 C2, B23Q 15/00 (01/10/2012) “A device for creating programs, a device for numerical program control, a method for creating programs” describes an automatic compensator that simplifies the design process of a product processing program by automatically taking into account nominal sizes and tolerances when preparing contours processing. This solution is indirectly related to the described invention, despite the mutual correspondence of a number of blocks, and does not include the functions realized by the described touch control unit.

US patent 3764813 A, G01B 11/00 (09/10/1973) "Coordinate recognition system" describes a device that is an infrared sensor frame, which is part of the described touch control unit, which is based on a projection-sensor system that allows you to convert the surface of the coordinate engraving machine into the touch screen of a computer connected to the machine, which increases the capabilities and functionality of this device and makes it more complete from a technical point of view in terms of implementation the board machine.

Known number RU 2438849 (06.06.2007) "Device for creating programs, a device for numerical program control, a method of creating programs closest analogue of the claimed invention." The device described in the patent is the closest analogue of the described invention, relates to mechanical engineering and can be used to control the machining of workpieces using a program of numerical program control (CNC). The CNC machining device contains a device for creating programs. This device provides the creation of a program based on the form data of the workpiece and the tolerance data for the form data. The device comprises a unit for calculating the target dimensions of the machining, a processing unit for deforming the shape data, and a unit for creating a machining program. Tolerance data includes positioning information regarding how to move graphic elements. The form data deformation processing unit is configured to set positions of graphic elements after moving based on said position change information

For machining such an area as landing (pairing), and obtaining dimensional tolerance associated with the function or operational characteristics of the object, machining of which leads to the creation of the product, you must have a CNC program for machining, which reflects the target size of machining, taking into account the fit or dimensional tolerance. In particular, the target machining size can be a value different from the nominal size in the case of fit or tolerance, when the permissible upper and lower limit deviations (the largest limit size and the smallest limit size) are asymmetric with an offset to any of the limit sizes (the largest limit size and the smallest size limit).

When directly creating (modifying) the CNC program for machining, taking into account the product drawings, the operator calculates the target machining size manually or using a calculator, and the coordinate compensated based on the calculation result is entered into the CNC program for machining. With this method, there is the likelihood of an incorrect calculation or input error, and the created NC program for machining becomes unreliable, since it is difficult to modify this program.

To solve this problem, a method is proposed that allows direct recording of information on nominal sizes and tolerances (dimensional tolerances or the like) into the CNC program for machining and ensuring that the CNC device performs the machining process based on the recorded information.

This invention proposes a device for creating programs made with the possibility of creating, based on the mold data of the workpiece and the tolerance data for the said mold data, a CNC program for machining reflecting the tolerance data on the mold data, including a unit for calculating the target dimensions of the machining with the ability to calculate the target dimensions of the machining for the workpiece on the basis of form data and tolerance data; a form data deformation unit configured to set positions after moving for graphic elements included in the form data based on the target machining sizes calculated by the calculation unit of the machining target sizes and the shape data so that the size between the graphic elements is consistent with appropriate target machining size; and a unit for creating a machining program configured to create an NC program for machining using form data and the aforementioned position of each graphic element after the movement specified by the form data deformation unit, wherein the form data deformation unit is configured to set the positions of the graphic elements after moving based on the change of position information regarding how to move graphic elements.

The above device performs functions similar to the described electronic unit for touch control of coordinate machines, but has a number of significant drawbacks: the use of this unit leads to the need for structural changes to the machine system, which in turn leads to the need to manufacture or purchase a new machine with the inclusion of this device creating programs; management is not intuitive, despite the significant simplification of the operator; The device has a number of design limitations in connection with the use of integrated CAD systems.

All of the above disadvantages greatly complicate the work of the machine operator in using both the electronic unit itself and in the development and updating of programs for specifying product processing loops.

The objective of the described electronic block touch control coordinate machines is to simplify the working conditions of the operator with coordinate engraving and milling machines. Technical results include the creation of a sensor system that converts the working surface of any coordinate machine into a touch control mechanism; projection of computer-aided design (CAD) systems pre-installed on a computer connected to the coordinate machine, on the working surface of the machine using a projector; a system for interrupting the execution cycle of a product processing program when foreign objects get into the processing field or the operator is in close proximity to the processing area.

A distinctive feature of the invention is the interaction with the software of the computer connected to the coordinate machine, using the working surface of the machine, after installing the described unit, which is a projection touch infrared display, which is a touch control system that includes an infrared sensor frame and a projector; The installed touch control system is a multifunctional device that controls the movement of the tool by monitoring the overlapping of the lines with an infrared photo sensor - infrared LED, infrared sensor frame, which includes routines for controlling the accuracy of cutting. The touch control system also monitors the location of excess objects in the processing field. This operation is also performed by monitoring the overlap of the lines of the infrared photosensor - infrared LED; touch data processing is carried out by a data processing unit including a microcontroller, whose outputs are connected to infrared photosensors of an infrared sensor frame, which makes it possible to form a coordinate grid. Information about the status of the outputs from the microcontrollers is sent to the computer using the data exchange unit, which includes microcircuits with the capabilities of USB-UART converters. Formulated features form a fundamental difference between this invention and existing analogues.

In FIG. 1 shows a block diagram of the described control unit: 1 - Infrared sensor frame; 2 - Projector; 3 - Information processing unit; 4 - data exchange unit; 5 - Computer connected to the coordinate machine. Data flow directions are indicated by arrows.

In FIG. 2 shows a structural diagram of the invention: 6 - Microcontroller assembly that processes the signal from infrared photosensors; 7 - Line ports for the output of microcontrollers to infrared LEDs; 8 - A line of input ports of microcontrollers for infrared photosensors; 9 - Infrared LEDs; 10 - Infrared photosensors; 11 - Data line; 12 - Filter capacitor.

In FIG. 3 shows the image of the functional areas of the infrared sensor frame: 13 - Area emergency stop; 14 - Area of transfer to the state of preparation for processing; 15 - Processing area; 16 - Location of the workpiece.

The device consists of a projector 2, mounted above the working surface of the coordinate machine, an infrared sensor frame 1, located along the contour of the working surface of the machine, consisting of infrared LEDs 9 and photosensors 10 connected respectively to the lines of the output ports 7 and the lines of the input ports 8, the electronic processing unit data 3 and data exchange unit 4, executed in a single metal case for shielding sensitive electronic components from background noise. The projector 2 is positioned so that the dimensions of the projected surface of the desktop of the computer 5 connected to the coordinate machine are scaled in accordance with the dimensions of the infrared sensor frame 1. This ensures that the touch position of the control elements matches the program position by analogy with the movements of a computer mouse.

A capacitor 12 at the input is necessary to filter the input interference of the power source of the electronic part of the device. The data processing unit 3 includes a system of microcontrollers 6. The number of microcontrollers 6 is selected in accordance with the resolution of the infrared frame 1, that is, it depends on the density of the arrangement of infrared components 9 and 10. Data from the microcontrollers is processed by the central processor of microprocessor assembly 6, which converts data from the input line 8 to the corresponding coordinate, data about which is sent to the computer via USB interface via USB-UART converters via the data exchange unit 4.

The described block has several operating modes: 1. Processing preparation mode. In this state, all block subsystems are active, the machine tool is at the zero point. When you start the computer 5, connected to the machine, the projector 2 is started, the infrared frame 1 is active.

Data on the status and availability of the equipment is received by the data processing unit 3 through the input ports of the input port line 8 of the microcontroller assembly 6 from peripheral devices 1 and 2. The readiness for operation of the infrared touch screen 1 is determined by the activity of all input port line ports 8 connected to the infrared photosensors 10 of the infrared frame 1 (the coordinate grid is active and does not cross). The job and placement of the workpiece 16 is done manually on the working surface of the machine within the processing area 15, corresponding to the limit positions of the tool along the axes of the working surface of the coordinate machine. If the operator deals with the processing of sheet blanks, it is possible to place them on the working surface of the machine. Then the task of cutting contours is made directly on the workpiece. The computer-aided design environment projected by using projector 2 onto the work surface of the machine allows the operator to develop product processing loops directly on the work surface of the coordinate machine. In this case, the input tool is not a computer mouse, but the operator’s finger, which performs operations in the coordinate grid of the infrared sensor frame 1. To limit the processing contours, the operator must use the finger in the coordinate grid of the infrared frame 1 to draw the contours of the workpiece before starting the processing directly. This is necessary for the correct operation of the system in cutting control mode. Product processing is carried out only in the absence of unnecessary objects in the coordinate grid field of the infrared sensor frame 1.

2. Cutting control mode. In this mode, projector 2 is inactive. The infrared sensor frame 1, the data processing unit 3 and the data exchange unit 4 are active. On the infrared frame 1, the processing emergency stop area 13 is highlighted. This is realized by writing information about this area to the microcontrollers of the data processing unit 3. The state of the photosensors 10 of the infrared sensor frame 1, included in the emergency stop area 13, are interrogated by the controllers during any operation mode of the touch control unit. This area goes beyond the boundaries of the working surface of the machine and is implemented as a prominent ledge of a rectangular coordinate grid. If an operator or other object’s finger gets into this area, a command is sent to stop processing through the data processing system 3, consisting of microprocessor assembly 6, and data exchange system 4. If foreign objects enter the area, except for emergency stop area 13, which is not included in the processing loops, the processing is interrupted. Until the processing is completed and the tool is moved to the zero point, this block operation mode is executed.

3. Standby time. In this mode, the infrared sensor frame 1, the data processing unit 3 and the data exchange unit 4 are also active. This mode is intermediate and is entered for translation into the preparation processing mode as necessary by the operator. In this mode, the emergency stop area 13 performs the function of the activation area of the start of the processing cycle along the specified processing loops. To do this, the operator places a finger in the emergency stop area 13 for 2 seconds, then the process starts again.

This electronic unit has a robust design that provides relevant information for processing, ensuring the accuracy of the positioning of the tool, as well as the safety and ease of operation of the operator of the coordinate machine.

Claims (4)

1. A device for touch control of a coordinate machine, comprising an infrared sensor frame, an information processing unit associated with a data exchange unit, and a visualization unit, said frame being made with a rectangular contour with the possibility of placing a coordinate machine on the desktop surface and includes infrared arrays LEDs located on two adjacent sides of the frame, and a line of infrared photosensors opposite them on other sides of the frame, while the information processing unit includes It includes a microcontroller, the terminals of which are connected with a line of infrared photosensors and which is configured to measure signal levels from photosensors, and the data exchange unit contains a microcontroller configured to connect to a personal computer via RS232 protocol via a USB port. 2. The device according to p. 1, characterized in that the visualization unit is made in the form of a digital projector with the ability to output information from a personal computer to the work surface of the machine. 3. The device according to p. 1, characterized in that the infrared photosensors are made in the form of infrared photodiodes, phototransistors or photoresistors. 4. The device according to p. 1, characterized in that the said frame is made monolithic, folding or prefabricated.

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